Claim Term is Defined by Specification and Prosecution History rather than Dictionary Definition

This case concerns how patent claim interpretation can be narrowed by the specification and prosecution history. The invention at issue was a surgical mesh plug that is placed on the weakened muscle wall area of a hernia so that muscle cells can grow on the plug and restore the strength of the muscle wall in the affected area. C. R. Bard, Inc. obtained U.S. Patent No. 5,356,432 on the surgical plug. When U.S. Surgical made a similar surgical plug, Bard sued for infringement. Though Bard prevailed at trial on claim 21, the District Court granted summary judgment of non-infringement as to claim 20. Bard appealed the District Court’s claim construction and final judgment on claim 20 to the Federal Circuit Court of Appeals.On appeal, Bard argued that the claimed surgical plug could be either pleated or non-pleated. U.S. Surgical maintained that claim 20 was limited to pleated surgical plugs only. Claim 20 was silent on its face as to whether the surgical plug required pleats or not. The Court said that the specification and prosecution history of a patent are parts of the intrinsic record that are to be primarily used to interpret claim meaning. Bard argued that dictionary definitions of patent claim terms override interpretations found in the intrinsic record. The Court disagreed. It stated that dictionary definitions can be helpful in interpreting ambiguous claim terms but they “do not require, or even allow, the Court to disregard the intrinsic record.” The Court did not find dictionary definitions of Bard’s claim terms governed over the intrinsic record because the specification defined the surgical plug in many places as being pleated.

In the “Summary of the Invention” section and elsewhere in the specification, the surgical plug is described as being pleated. Descriptions of the invention as a whole that contain limitations, as opposed to descriptions of a preferred embodiment, “are more likely to support a limiting definition of a claim term”. Even though “pleated” was not present in every usage of the claim term throughout the specification, the Court found “the plug claimed by the ‘432 patent is defined globally as requiring a pleated surface, which limits claim 20.”

The Court also reviewed the prosecution history and determined that because of Bard’s statements during prosecution and reexamination, claim 20 was limited to pleated surgical plugs. In the initial examination, the claim that ultimately became claim 20 was rejected on various grounds. Bard argued that one of the prior art patents on surgical plugs that formed the basis of the rejection lacked pleats, among other things. In an interview concerning this prior art patent, Bard “explicitly relied on pleating as a distinction over the prior art”. However, because other claims having an explicit pleating limitation were at issue in the interview, the Court concluded that “limiting claim 20 to require pleating based solely upon amendments and arguments made during the initial examination would likely be improper.”

Next, in reexamination of the patent, the examiner rejected claims 19 and 20 because they did not claim a pleated surgical plug. Bard responded to this rejection by “distinguish[ing] the plug contained in claims 19 and 20…on the basis of its plug having pleats.” The Court treated this as “an unequivocal statement constituting a clear disclaimer of scope in claim 20” that was not made in mistake and was accurate.

Accordingly, in affirming the District Court’s claim construction, the Court held that both the prosecution history and specification provided independent grounds to limit the claim interpretation. Thus, U.S. Surgical’s non-pleated surgical plug did not infringe Bard’s patent for pleated surgical plugs. Judge Prost concurred with the opinion, emphasizing that Bard clearly disclaimed the non-pleated coverage in the reexamination.

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